Large-scale Storage Research Articles

High-rate and selective conversion of CO2 from aqueous solutions to hydrocarbons

Electrochemical carbon dioxide (CO2) conversion to hydrocarbon fuels, such as methane (CH4), offers a promising solution for the long-term and large-scale storage of renewable electricity. To enable this technology, CO2-to-CH4 conversion must achieve high selectivity and energy efficiency at high currents. Here, we report an electrochemical conversion system that features proton-bicarbonate-CO2 mass transport management coupled with an in-situ copper (Cu) activation strategy to achieve high CH4 selectivity at high currents. We find that open matrix Cu electrodes sustain sufficient local CO2 concentration by combining both dissolved CO2 and in-situ generated CO2 from the bicarbonate. In-situ Cu activation through alternating current operation renders and maintains the catalyst highly selective towards CH4. The combination of these strategies leads to CH4 Faradaic efficiencies of over 70% in a wide current density range (100 – 750 mA cm-2) that is stable for at least 12 h at a current density of 500 mA cm-2. The system also delivers a CH4 concentration of 23.5% in the gas product stream.

A modified analytical model for predicting seismic behaviors of unanchored liquid storage tanks

Large-scale liquid storage tanks, which are generally constructed unanchored, would suffer from severe damages subjected to intensive earthquakes, e.g., uplift, shell buckling and piping connection fracture, or even failure. This paper aims to develop a modified analytical model for performance assessment of large-scale unanchored storage tanks subjected to earthquakes, with a special focus on the effect of the uplift behavior. The stiffness of the rotational spring at the base of the analytical model was derived from an artificial neural network (ANN) on the spring resistance function. For this purpose, finite element (FE) models of unanchored storage tanks for static analysis were first verified by using experimental and numerical results from literature. Subsequently, the static analysis was performed on a large-scale unanchored storage tank to obtain the spring resistance function, i.e., the overturning moment – uplift height relationship, and a parametric analysis was further developed. Accordingly, a database consisted of 324 FE models was generated to establish the ANN and the spring resistance function was consequently derived. Responses of the large-scale storage tank under different earthquakes obtained from the modified model were compared with the numerical simulation result and reasonable accuracy with deviations of −24% and − 14% on the peak uplift height and peak base shear force was witnessed, respectively.

Nonporous Oxide-Terminated Multicomponent Bulk Anode Enabling Energy-Dense Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are emerging as power sources for large-scale storage owing to their abundant and inexpensive sodium (Na) source, but their limited energy density hinders their commercialization. High-capacity anode materials, such as antimony (Sb), which are potential energy boosters for SIBs, suffer from battery degradation owing to large-volume-changes and structural instability. The rational design of bulk Sb-based anodes to enhance the initial reversibility and electrode density inevitably requires atomic- and microscale-considered internal/external buffering or passivation layers. However, unsuitable buffer engineering causes electrode degradation and lowers energy density. Herein, the rationally designed intermetallic inner and outer oxide buffers for bulk Sb anodes are reported. The two chemistries in the synthesis process provide an atomic-scale aluminum (Al) buffer within the dense microparticles and an external mechanically stabilizing dual oxide layer. The prepared nonporous bulk Sb anode maintained excellent reversible capacity at a high current density and Na-ion full battery evaluations with Na3V2(PO4)3 (NVP) showing negligible capacity decay over 100 cycles. The demonstrated buffer designs for commercially favorable micro-sized Sb and intermetallic AlSb shed light on the stabilization of high-capacity or large-volume-change electrode materials for various metal-ion rechargeable batteries.

Selectivity Control of Oxygen Reduction Reaction over Mesoporous Transition Metal Oxide Catalysts for Electrified Purification Technologies

Direct electrification of oxygen-associated reactions contributes to large-scale electrical storage and the launch of the green hydrogen economy. The design of the involved catalysts can mitigate the electrical energy losses and improve the control of the reaction products. We evaluate the effect of the interface composition of electrocatalysts on the efficiency and productivity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), both mechanistically and at device levels. The ORR and OER were benchmarked on mesoporous nickel(II) oxide and nickel cobaltite (NiO and NiCo2O4, respectively) obtained by a facile template-free hydrothermal synthesis. Physicochemical characterization showed that both NiO and NiCo2O4 are mesoporous and have a cubic crystal structure with abundant surface hydroxyl species. NiCo2O4 showed higher electrocatalytic activity in OER and selectivity to water as the terminal product of ORR. On the contrary, ORR over NiO yielded hydroxyl radicals as products of a Fenton-like reaction of H2O2. The product selectivity in ORR was used to construct two electrolyzers for electrified purification of oxygen and generation of hydroxyl radicals.

Smash: Flexible, Fast, and Resource-efficient Placement and Lookup of Distributed Storage

Large-scale distributed storage systems, such as object stores, usually apply hashing-based placement and lookup methods to achieve scalability and resource efficiency. However, when object locations are determined by hash values, placement becomes inflexible, failing to optimize or satisfy application requirements such as load balance, failure tolerance, parallelism, and network/system performance. This work presents a novel solution to achieve the best of two worlds: flexibility while maintaining cost-effectiveness and scalability. The proposed method Smash is an object placement and lookup method that achieves full placement flexibility, balanced load, low resource cost, and short latency. Smash utilizes a recent space-efficient data structure and applies it to object-location lookups. We implement Smash as a prototype system and evaluate it in a public cloud. The analysis and experimental results show that Smash achieves full placement flexibility, fast storage operations, fast recovery from node dynamics, and lower DRAM cost (<60%) compared to existing hash-based solutions such as Ceph and MapX.

Storing carbon dioxide for climate's sake: contradictions and parallels with enhanced oil recovery

An increase in carbon capture and storage (CCS) projects, including bioenergy with CCS (BECCS), has led to an urgent demand for storage sites, and Norway stands out for its ongoing and planned geological storage sites in a European context. Even though there are no commercial carbon dioxide enhanced oil recovery (CO2-EOR) projects in Norway and the North Sea, there is scientific literature linking CO2-EOR and CCS in this geographical region. CO2-EOR utilizes CO2 to extract additional oil, counteracting the climate change mitigation purpose of geological storage. This review article explores how CCS is represented in the scientific literature on CO2-EOR in the North Sea and Norway, with a focus on system synergies and contradictions in relation to climate change mitigation. The main themes in the scientific literature on CO2-EOR in the North Sea are climate change, economics, and geological feasibility. Monitoring, safety, and leakage in addition to transportation of CO2 are less salient. The results show that there are contrasting framings in the literature. One framing is that CO2-EOR is a gateway to large-scale storage which maintains, or even expands, the extraction of fossil fuels and contributes to a sustainable transition in the long run through knowledge building and shared infrastructure. In contrast, another framing is that CO2-EOR combined with CCS have goal conflicts and are therefore not compatible, illustrating complexities with geological storage. Finally, this study reflects on how techno-economic research on CO2 storage in the North Sea and Norway is furthered through critical social science perspectives.

Comparison of the volatile organic compounds in Citrus reticulata 'Chachi' peel with different drying methods using E-nose, GC-IMS and HS-SPME-GC-MS.

Citrus reticulata 'Chachi' peel (CRCP), which is named "Guangchenpi" in China, is a geographical indication product with unique flavor properties. CRCP has been used for centuries as a traditional genuine herb because of its excellent therapeutic effects. In addition, owing to its unique odor and high nutrition, it is widely used in various food preparations. Volatile organic compounds (VOCs) are regarded as an important quality marker for CRCP and are highly susceptible to effects in the drying process due to their thermal instability. In the current study, the main VOCs in CRCP were processed using different drying methods, including sun-drying, hot air drying, and vacuum-freeze drying. The VOCs were identified by the electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that the CRCP dried by vacuum-freeze exhibited the highest VOCs contents and retained the richest compounds compared to those dried by other methods, which indicated that vacuum-freeze drying is the most suitable for CRCP production. Furthermore, the chemometrics analysis revealed that the primary differential metabolites of the samples generated using different drying methods were terpenes and esters. Overall, our study would help better understand the VOCs present in CRCP with different drying methods. The outcomes of the current study would guide the drying and processing of CRCP, which is beneficial for large-scale storage and industrial production of CRCP.

An adaptive charge control strategy for participation of neighbourhood battery energy storage systems in frequency stability

Neighbourhood Battery Energy Storage System (N-BESS) is a new scale of energy storage that is expected to have a potential role in modern power systems stability. In the literature, there is a lack of studies that proposed a smart engagement of N-BESS in the frequency stability. In this paper, an adaptive charge control strategy for the N-BESS has been proposed to enhance the frequency stability while maintaining a fair State-of-Charge (SOC) levels for N-BESS. Also, a collaborative framework for large-scale Battery Energy Storage System (L-BESS) with N-BESS has been introduced, in which the N-BESS play an auxiliary role in frequency stability. In this study, a number of system uncertainties, including N-BESS SOC, load consumption, wind farm generation, and contingency size and location, have been considered. The simulation has been carried out in the Simplified 14-Generator Model of the South East Australian Power System over one-year simulation using DIgSILENT/PowerFactory software and Python interface. The results have demonstrated that a higher SOC levels of N-BESS under the proposed strategy have been maintained compared to that of the conventional strategy. Moreover, when the L-BESS collaborated with the N-BESS under the proposed framework, the best frequency stability with highest SOC levels of N-BESS have been obtained; at the same time less discharged power by the L-BESS was noted compared to that when the L-BESS participated individually which indicated that a smaller L-BESS size would be required if it collaborated with N-BESS in frequency stability service.

Success factors in the creation of a CCS Hub

Carbon capture and storage (CCS) has the potential to significantly reduce emissions from industrial processes including gas processing and heavy industry. INPEX has a corporate goal to reduce scope 1 and 2 emissions intensity by 30% or more by 2030 on a path to net zero by 2050. Central to these goals is reduction of emissions associated with the Ichthys LNG operation, located on the Middle Arm of Darwin Harbour. Key to the reduction of emissions from Ichthys LNG is the development of a large-scale efficient CCS facility close to Darwin. To this end, INPEX (as Operator) and Joint Venture participants TotalEnergies and Woodside Energy were recently awarded the G-7-AP block in the promising Petrel Sub-basin. The work program associated with this bid includes new 3D seismic, a two-well-appraisal drilling campaign and a comprehensive post-well analysis program to prove up the previously identified storage intervals and allow INPEX to determine the potential storage capacities of these intervals. Scale is a critical driver of the efficiency of a storage solution, so INPEX is working collaboratively with wider industry, government and the CSIRO on the development of the Northern Territory Low Emissions Carbon Capture, Utilisation and Storage Hub business case which seeks to identify and map the pathway for the development of a large-scale multi-sink carbon storage network. This paper will provide an update on INPEX’s vision for the role it intends to play in the development of this Hub.

The surface challenges of underground hydrogen storage – pre-feasibility studies at the Otway International Test Centre, Victoria

Underground hydrogen storage (UHS) has the potential to overcome the infrastructure and safety challenges of large-scale hydrogen storage, support long-term supply security and decrease delivery costs through economies of scale. Depleted hydrocarbon reservoirs and saline aquifers are likely to be significant contributors to UHS capacity in Australia. The principles of subsurface hydrogen storage in porous reservoir rocks are based on experience from both natural gas and carbon dioxide storage projects. However, as field-scale testing is required to demonstrate and mature the technology, a pre-feasibility study of the potential for an early UHS demonstration at the Otway International Test Centre (OITC) has been undertaken. Pre-feasibility studies have shown that while the characterisation of the subsurface storage reservoir is the most important aspect of the site-selection process, above-ground factors, such as facilities design, the logistics of hydrogen supply and the regulatory environment, significantly affect project design. Existing technologies require only minor adaptation to provide the surface infrastructure for a UHS project, but the logistics of hydrogen supply may be a significant factor in the scope of a demonstration project.

Including sub-surface uncertainties in CCS hub investment decision making – a case history

Large-scale carbon capture and storage (CCS) hub investments require design choices regarding sizing (in Mt-CO2/year) and project build-out phasing. Investments in capture and transport represent the majority of overall project capex, with the ‘size’ of that infrastructure ideally optimised to capture and deliver steady rates over the asset lifetime. However, there is a risk that the sub-surface injection (i.e. storage) rate cannot be sustained at the specified capture rate. The investment risk in sizing major capture and transport equipment therefore lies in the uncertainty surrounding future dynamic performance of the storage site(s). This paper builds on a previous investigation for the Surat Basin, examining the role that sub-surface uncertainties play in this hub- sizing risk. Articulating the value of investment in additional appraisal information, shows that the acquisition of critical, uncertainty-defining data can reduce final investment risk in capture and transport, helping to ‘right size’ the hub build. Screening-stage modelling of technical and economic uncertainty plays a crucial role, characterised with a target unit technical cost (UTC) that represents the life-cycle, constant real-terms, carbon price ($/t) required for storage that would result in a break-even economic development. The presence of pre-development uncertainties in long-term dynamic performance, and the need for appraisal to reduce that uncertainty, effectively increase the required break-even storage price. Alternatively, ignoring that uncertainty could lead to under-performance of the storage resource (inability to sequester at the capture design-rates) and significant over-investment in capture and transport infrastructure, increasing the overall cost of CO2 sequestration.

Microfluidic hydrogen storage capacity and residual trapping during cyclic injections: Implications for underground storage

Long-term and large-scale H2 storage is vital for a sustainable H2 economy. Research in underground H2 storage (UHS) in porous media is emerging, but the understanding of H2 reconnection and recovery mechanisms under cyclic loading is not yet adequate. This paper reports a qualitative and quantitative investigation of H2 reconnection and recovery mechanisms in repeated injection-withdrawal cycles. Here we use microfluidics to experimentally investigate up to 5 cycles of H2 injection and withdrawal under a range of injection rates at shallow reservoir storage conditions. We find that H2 storage capacities increase with increasing injection rate and range between ∼10% and 60%. The residual H2 saturation is in the same range between cycles (30–40%), but its distribution in the pore space visually appears to be hysteretic. In most cases, the residually trapped H2 reconnects in the subsequent injection cycle, predominantly in proximity to the large pore clusters. Our results provide valuable experimental data to advance the understanding of multiple H2 injection cycles in UHS schemes.

Hydrogen tightness evaluation in bedded salt rock cavern: A case study of Jintan, China

Hydrogen is regarded as one of the most important energy sources for the future. Safe, large-scale storage of hydrogen contributes to the commercial development of the hydrogen industry. Use of bedded salt caverns for natural gas storage in China provides a new option for underground hydrogen storage (UHS). In this study, the physical properties of multicomponent gases in UHS and salt rock are reviewed and discussed, along with the flow of hydrogen in the surrounding salt rock. Mathematical models of the two-phase multicomponent flow of the gas–brine system in the UHS were established. A numerical model of a simplified elliptical salt cavern was built to simulate the migration of the gas–brine system in the UHS. The hydrogen tightness of the UHS was evaluated through simulation with different storage strategies, salt rock and interlayer permeabilities, and gas components. The results indicate that: (1) Cyclic injection and withdrawal facilitate hydrogen leakage, which is accelerated by increasing the frequency. (2) The huff-n-puff of hydrogen gas in the injection and withdrawal cycles forces the gas into pore space and enhances the relative permeability of the gas phase. The migration of hydrogen and brine weakens the hydrogen tightness. Brine saturation is an important index for evaluating the hydrogen tightness of UHS. (3) The leakage rate of UHS increases with an increase in the permeability of the salt rock and interlayer and the total thickness of the interlayers. The average permeability Kwa weighted by the thickness of layers for the bedded salt formation is proposed to integrate three variables to facilitate field application of the simulation results. The critical Kwa is less than 3.02 × 10−17 m2 if the recommended annual hydrogen leakage rate is less than 1%. (4) The difference between hydrogen and other gas species is another important factor in the leakage rate and should be considered. This study provides theoretical guidance for evaluating the feasibility of UHS in salt caverns and site selection in China.

Utilizing publicly available datasets for identifying offshore salt strata and developing salt caverns for hydrogen storage

Abstract Hydrogen is expected to play a key role in a future climate-neutral economy by decarbonizing ‘hard to abate’ sectors, and importantly act as an energy carrier to balance intermittent renewable energy production, which, if stored, could be used to address grid-scale energy demands. It is evident that for unlocking the vast potential of hydrogen technologies, large-scale hydrogen storage with the capability of fast cyclic operations needs to be secured. Underground salt caverns, where decades of operational experience exist, offer an attractive option for hydrogen storage due to the high hydrogen sealing potential of salt, capability for large injection/withdrawal flow rates and capacity for large volume storage. This study presents a novel methodology for selecting offshore salt cavern sites based on publicly available datasets, which leads to eventually estimating regional hydrogen storage capacities. The Southern North Sea was investigated and a case study detailing a single diapiric salt structure is presented, demonstrating the strength and practicality of the framework as well as highlighting the potential of offshore salt cavern storage of hydrogen in the decarbonization energy journey of the UK.

Energy saving and peak load shifting performance of tail water source heat pump integrated with large-scale thermal storage pool space heating system in technology park

In cities, there are thousands of wastewater treatment plants. The treated tail water drained from them is clean relatively, and has a stable flow rate. Extracting heat from it through tail water source heat pumps (TWSHP) for space heating can decrease the building heating energy consumption significantly. Besides, by integrating with thermal energy storage (TES), it can realize the goal of peak load shifting, especially in commercial buildings. However, there is few reports on its experimental investigations or engineering applications till now. To promote the application of TWSHP integrated with TES system, it was designed for the space heating of a technology park in Beijing, and a control method was proposed to decrease the operating cost by using the valley electricity. Then, utilizing its operating parameters in the heating season of 2021–2022, its heating performance was analyzed. Results indicate that the proposed system has good heating performance. The average COPs of TWSHP units and the system in the heating season are 7.08 and 4.41, respectively. Compared with gas-fired boiler, its carbon emission decreased by 62.53%. By using the TES system, the power consumption during valley period of power grid increases by 581.23%, realizing the goal of peak load shifting.

Discrete Hyperchaotic S-Box Generation for Selective Video Frames Encryption

Cloud computing has become a significant technology with rapid popularization offering many services with highly effective computation and large-scale storage solutions. As multimedia files are growing explosively, securely storing them for authorized access is a major task. Concentrating on video file storage in a public cloud environment, the security and privacy of those outsourced videos are the major concerns. A selective frame encryption approach is proposed to encrypt the semantic elements of the selected frames of High Efficiency Video Coding (HEVC) compressed videos by storing them in the cloud. The semantic elements of HEVC videos are extracted and encrypted by a modified Advanced Encryption Standard (AES) operation in CFB mode with a Substitution-Box (S-Box). A dynamic, nonlinear 2D discrete hyperchaotic mapping-based S-box generation method is proposed to enhance security by providing good confusion, diffusion, and scrambling. The performance analysis of generated S-box and experimental results show that the proposed selective encryption highly resists attacks and encrypts with reduced time complexity.

Role of methane as a cushion gas for hydrogen storage in depleted gas reservoirs

Depleted natural gas reservoirs play an important role as a viable option for large-scale hydrogen storage and production. However, its deployment depends on the accurate knowledge of the cushion gas (such as CH4, CO2, and N2) compositions, which are key components affecting the rock-fluid interfacial phenomenon. In addition, there are currently few reported studies on rock/brine/gas-mixture wettability and gas-mixture/brine surface tension representing this type of reservoir. Hence, we report the feasibility of using CH4 as a cushion gas (in the presence of CO2 and N2) for H2 storage at various pressures (500 up to 3000 psi), temperatures (30 up to 70) oC, and salinities (2 up to 20) wt.% using drop shape analyzer equipment. Contact angle (CA) and surface tension (ST) experiments were extensively conducted for the different gas mixtures (H2–CH4–CO2–N2) to establish relevant data for H2 storage in depleted gas reservoirs.Our result indicates that unless when the rock's initial wetting state is altered, the studied gas-mixture compositions (Test case 1: 80% H2 – 10% CH4 – 5% CO2 – 5% N2; case 2: 70% H2 – 20% CH4 – 5% CO2 – 5% N2; case 3: 60% H2 – 30% CH4 – 5% CO2 – 5% N2; case 4: 50% H2 – 40% CH4 – 5% CO2 – 5% N2; case 5: 40% H2 – 50% CH4 – 5% CO2 – 5% N2; case 6: 30% H2 – 60% CH4 – 5% CO2 – 5% N2; and case 7: 20% H2 – 70% CH4 – 5% CO2 – 5% N2) will exhibit comparable wettability behavior as the CAs ranged between [20 to 41°] irrespective of the reservoir pressure, temperature, and salinity. ST decreases with increasing temperature and linearly with increasing pressure. ST for each gas mixture increased with salinity. ST decreases systematically with increasing CH4 fraction (at any given salinity, temperature, and pressure) with the highest observed in Test case 1 and the lowest in Test case 7 compositions. Test cases 3 and 4 with H2 (50–60%) and CH4 (30–40%) fractions was selected as the optimal gas mixture based on CA and ST for H2 storage and withdrawal. The study's findings offer precise and useful input data for the reservoir-scale simulation used in geo-storage optimization in depleted natural gas reservoirs.

Study of a passive radiative cooling coating on chemical storage tanks for evaporative loss control

All-day passive radiative cooling is a promising cooling technique achieves cooling without any energy input, thereby attracting tremendous attention. Most of the studies focus on building applications, but there remains a lack of information on other potential applications of radiative cooling systems. Herein, we report an application of a polymeric passive radiative cooling coating (PRCC) on the exterior surface of chemical storage tanks, which is often overlooked but exhibits great potential to efficiently control the evaporative loss of the chemicals. The PRCC exhibits strong solar reflectivity (96.2%) and emissivity (95%) in the mid-infrared wavelength range. According to the results of an outdoor test on a small-scale chemical storage container, the PRCC achieves 81.4%, 54.1%, and 19.8% of chemicals saved compared with a raw container, container painted with commercial white paint (CWP), and the shaded raw container, respectively. A numerical simulation is also conducted to estimate the chemical standing loss from an industrial large-scale chemical storage tank. It is found that the PRCC can achieve a saving of over 50% of the chemical compared with commercial white paint for a chemical storage tank, showing a promising potential to be applied on chemical storage systems.

Management of Geospatial Data using Blockchain

The data generated all over the world is ever increasing. With this increase, the need to secure and regulate the use of data has become necessity. This can be achieved using blockchain. In case of geospatial data, which is of very large size and mostly unaltered once generated, storing it on blockchain is a challenging task. Storing it on-chain is practically not feasible as of now but storing actual off-chain and just storing metadata on the blockchain is the most practical & feasible solution available currently. To store large amount of data and at the same time provide the efficient & permission-based access to it, we have proposed a solution. Our solution will maintain a record of authorized nodes and the blockchain of metadata of large geospatial data. To provide an efficient querybased access, we will use MongoDB to store the pointer to the nodes in the blockchain to directly access the block. The storage of just metadata on the blockchain will reduce the complete blockchain size considerably. This model provides both the efficient & secure large scale storage while providing the efficient query & access mechanism at the same time. Also, we will use graphical way to grant permission

A detailed comparative performance study of underground storage of natural gas and hydrogen in the Netherlands

With the expected increase in the use of hydrogen as an energy carrier, large-scale underground storage sites will be needed. Unlike underground natural gas storage (UGS), many aspects on the performance of underground hydrogen storage (UHS) are not well understood, as there is currently no UHS in use for energy supply. Here we present the results of a detailed comparative performance study of UGS and UHS, based on an inflow/outflow nodal analysis. Three UGS sites in depleted gas fields and one in a salt cavern cluster in the Netherlands are used as case studies. The results show that although hydrogen can be withdrawn/injected at higher rates than natural gas, this can be limited by technical constraints. It also indicates that wider ranges of working pressures are required to increase the storage capacity and flow performance of an UHS site to compensate for the lower energy density of hydrogen.